Added config file import and checking and reworked to support multiple airports

.gitignore

@@ -1 +1,2 @@
-node_modules
+node_modules
+*-metars.json

config.json

@@ -0,0 +1,8 @@
+{
+    "outputdir": "/var/www/weather",
+    "icaos": ["CYWG", "KJFK"],
+    "siteurl": "https://example.com",
+    "rss-baseurl": "https://example.com/weather",
+    "check-interval": 10,
+    "loglevel": 4
+}

index.js

@@ -1,24 +1,71 @@
 import RSS from "rss";
 import axios from "axios";
 import fs from 'fs';
+import path from 'path';
 
 const API_URL = "https://aviationweather.gov/api/data/";
 const METAR_SERVICE = "metar";
-const feedOutput = process.env.METAR_FEED_OUTPUT;
-const icao = process.env.METAR_ICAO;
-const rssMetarOptions = {
-    title: icao + " METAR",
-    description: "METAR feed for " + icao + " Airport",
-    feed_url: process.env.METAR_FEED_URL,
-    site_url: process.env.METAR_SITE_URL,
-    generator: "https://git.entropic.pro/Aiden/metar-rss"
+const generatorURL = "https://git.entropic.pro/Aiden/metar-rss";
+
+/** Load config file */
+const configFile = "./config.json";
+let configData;
+try {
+    configData = JSON.parse(fs.readFileSync(configFile));
+} catch (err) {
+    console.error(err);
+    console.warn("Unable to read config file, using defaults");
 }
-const checkInterval = 10 * 1000 * 60; //10 Minute Check Interval
+
+/** Verify config data **/
+if (Number(configData["loglevel"]) == NaN) {
+    console.warn("loglevel is not a number, using 4");
+    configData["loglevel"] = 4;
+}
+const loglevel = Number(configData["loglevel"]);
+
+try {
+    if (!fs.lstatSync(configData["outputdir"]).isDirectory()) {
+        if (loglevel >= 4) console.warn("outputdir is not a directory, using current folder");
+        configData["outputdir"] = __dirname;
+    }
+} catch (err) {
+    if (loglevel >= 3) console.error(err);
+    if (loglevel >= 4) console.warn("error finding outputdir, using current folder");
+    configData["outputdir"] = __dirname;
+}
+const outputDir = configData["outputdir"]
+
+if (!Array.isArray(configData["icaos"])) {
+    if (loglevel >= 4) console.warn("icao config must be an array of ICAO codes, using default");
+    configData["icaos"] = ["KJFK"];
+}
+const icaos = configData["icaos"];
+
+try {
+    new URL(configData["siteurl"]);
+} catch (err) {
+    if (loglevel >= 4) console.warn("siteurl is not a valid URL, using example.com");
+    configData["siteurl"] = "https://example.com"
+}
+const siteURL = new URL(configData["siteurl"]);
+
+try {
+    new URL(configData["rss-baseurl"]);
+} catch (err) {
+    if (loglevel >= 4) console.warn("rss-baseurl is not a valid URL, using example.com");
+    configData["rss-baseurl"] = "https://example.com"
+}
+const rssBaseURL = new URL(configData["rss-baseurl"]);
+
+if (Number(configData["check-interval"]) == NaN) {
+    if (loglevel >= 4) console.warn("check-interval is NaN, using 10 minutes");
+    configData["check-interval"] = 10;
+}
+const checkInterval = Number(configData["check-interval"]) * 1000 * 60;
 
 
-let lastMetar;
-let metarRSS = new RSS(rssMetarOptions);
-
+/** Start Service **/
 checkMetar(); //Inital check run
 const metarCheckJob = setInterval(checkMetar, checkInterval); //Run the check every interval
 
@@ -26,53 +73,109 @@ const metarCheckJob = setInterval(checkMetar, checkInterval); //Run the check ev
  * Pulls the current metar and adds it to the feed if it is new
  */
 function checkMetar() {
-    console.log("Checking METAR for " + icao);
-    getMetar().then(res => {
-        if (res.data != lastMetar) {
-            console.log("New METAR: " + res.data);
-            newMetar(metarRSS, res.data);
-            writeFeed(metarRSS);
-            lastMetar = res.data;
-        }
-    });
+    for (let i = 0; i < icaos.length; i++) {
+        let icao = icaos[i];
+        if (loglevel >= 7) console.log("Checking METAR for " + icao);
+        getMetar(icao).then(res => {
+            let metarFile = icao+"-metars.json";
+            let metars = [];
+            if (fs.existsSync(metarFile)) 
+                metars = JSON.parse(fs.readFileSync(icao+"-metars.json"))["data"];
+
+            if (res.data != metars[0]) {
+                if (loglevel >= 6) console.log("New METAR: " + res.data);
+                metars.unshift(res.data);
+                if (metars.length > 20) metars.pop();
+                fs.writeFileSync(metarFile, JSON.stringify({"data": metars}));
+
+                let items = [];
+                for (let i = 0; i < metars.length; i++) {
+                    if (newMetar(metars[i]) != undefined)
+                        items.push(newMetar(metars[i]));
+                }
+                
+                let outputPath = METAR_SERVICE + "/" + icao;
+                writeFeed(generateFeed(METAR_SERVICE, icao, items, outputPath), outputPath);
+            }
+        });
+    }
 }
 
 /**
  * Adds a new METAR to the given RSS Feed
- * @param {*} rss - RSS Feed to add the entry to
- * @param {*} metar - metar data to add
+ * @param {RSS} rss - RSS Feed to add the entry to
+ * @param {String} metar - metar data to add
+ * @returns {Object} - Object of RSS Item Data
  */
-function newMetar(rss, metar)  {
+function newMetar(metar)  {
     let metarSplit = metar.split(" ");
     let date = new Date(Date.now());
     let eventDate = new Date(Date.UTC(date.getFullYear(), date.getMonth(), Number(metarSplit[2].substring(0,2)), Number(metarSplit[2].substring(2,4)), Number(metarSplit[2].substring(4,6))));
 
-    rss.item({
+    let item =  {
         title: metarSplit[0] + " " + metarSplit[1] + " " + metarSplit[2],
         description: metar,
         url: API_URL + METAR_SERVICE,
         guid: metarSplit[1] + metarSplit[2],
         date: eventDate
-    });
+    };
+    return item
 }
 
 /**
  * Pulls METAR data from the API
+ * @param {String} icao ICAO Airport Code
  * @returns Axios generated GET Request Response
  */
-function getMetar() {
+function getMetar(icao) {
     let requestURL = API_URL + METAR_SERVICE + "?ids=" + icao;
     return axios.get(requestURL);
 }
 
 /**
- * Writes the given RSS feed to the specified file
- * @param {*} rss - RSS Feed to Write
+ * Generates and populates a feed for the given details
+ * @param {String} service eg. "metar"
+ * @param {String} icao ICAO Airpot Code
+ * @param {Array} items Array of Objects containing RSS item details
+ * @param {String} outputPath path for this Service + ICAO
+ * @returns {RSS} RSS Feed with populated items
  */
-function writeFeed(rss) {
+function generateFeed(service, icao, items, outputPath) {
+    let feedURL = rssBaseURL;
+    feedURL.pathname = feedURL.pathname.concat(outputPath);
+    
+    let feedOptions = {
+        title: icao + " " + service,
+        description: service + " feed for " + icao + " Airport",
+        feed_url: feedURL,
+        site_url: siteURL,
+        generator: generatorURL
+    }
+    let feed = new RSS(feedOptions);
+
+    for (let i = 0; i < items.length; i++) {
+        feed.item(items[i]);
+    }
+
+    return feed;
+}
+
+/**
+ * Writes the given RSS feed to the specified file
+ * @param {RSS} rss - RSS Feed to Write
+ * @param {String} outputPath path for this Service + ICAO
+ */
+function writeFeed(rss, outputPath) {
     let xmlFeed = rss.xml({indent: true})
+    let fullPath = path.join(outputDir, outputPath);
+    let fullPathFile = path.join(fullPath, "rss.xml");
+
+    if (!fs.existsSync(fullPath)){
+        fs.mkdirSync(fullPath, { recursive: true });
+    }
+
     try {
-        fs.writeFileSync(feedOutput, xmlFeed);
+        fs.writeFileSync(fullPathFile, xmlFeed);
     } catch(err) {
         console.error(err);
     }